Hi

No problem to open, modify and save the theme
But when I want to test it on W11 24h2 with WSB, I have the error message that the msstyles file is not good (same message when trying to test the default theme, so not a file problem)

And since version 26100.1301 of the aero.msstyles file, it is not possible to modify it, I have the error message mentioned above

Can you modify the aero.msstyles 26100.1301 file and apply it in Windows or just test it with WSB (if you use W11 24h2 of course) ?